P1055 [NOIP2008 Popularization Group] ISBN number

#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
    
    
	char a[15];
	int b[10],m=0,sum=0;
	for(int i=0;i<13;i++){
    
    
		cin>>a[i];
		if(a[i]!='-' && a[i]!='X'){
    
    
			b[m]=int(a[i]);
			m++;
		}
	}
	for(int i=0;i<9;i++)
		sum=b[i]*(i+1)+sum;
	if(sum%11==10 && a[12]=='X')
		cout<<"Right"<<endl;
	else if(sum%11!=10 && a[12]!='X' && sum%11==int(a[12]))
		cout<<"Right"<<endl;
	else{
    
    
		for(int i=0;i<12;i++)
			cout<<a[i];
		if(sum%11==10)
			cout<<'X'<<endl;
		else
			cout<<sum%11<<endl;
	}
	return 0;
}

The first magnetic field is wrong, because I used the data type conversion under python thinking!
Consider the following example:

#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
    
    
	cout<<int('2')<<endl;
	return 0;
}

Output:

50

The reason is obvious: when you try to use int for type conversion, you can actually get the corresponding ascii code, not the integer 2!
Ah, I suddenly forgot the '9'-'0'=9 Dafa that I have seen many times? In other words, the integer character minus '0' becomes the corresponding integer, just fine-tune the code according to this idea:

#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
    
    
	char a[15];//储存输入的字符串
	int b[10],m=0,sum=0;
	for(int i=0;i<13;i++){
    
    
		cin>>a[i];
		if(a[i]!='-' && a[i]!='X'){
    
    
			b[m]=a[i]-'0';//字符型转换为整型
			m++;
		}
	}
	for(int i=0;i<9;i++)
		sum+=b[i]*(i+1);
	if(sum%11==10 && a[12]=='X')
		cout<<"Right"<<endl;//单独考虑余数为10
	else if(sum%11!=10 && a[12]!='X' && sum%11==a[12]-'0')
		cout<<"Right"<<endl;
	else{
    
    
		for(int i=0;i<12;i++)
			cout<<a[i];
		if(sum%11==10)
			cout<<'X'<<endl;//实现紧凑输出
		else
			cout<<sum%11<<endl;
	}
	return 0;
}